The present invention relates to a new and improved grating composed of individual bars and serving for use with a rotatable opening roller provided with clothing.
In its more specific aspects, the grating of the present development is of the type wherein each grating bar has secured thereto a guide element formed of sheet material and extending over the length of the bar. Each such guide element comprises two band portions arranged adjacent each other and extending in the longitudinal direction of the bar. The first band portion forms a flat surface which rests on one side face or surface of the associated bar, and the second band portion forms a guide face or surface adjacent the clothing and extends in approximately tangential direction relative thereto. The spacing of the guide face or surface from the clothing is adjustable through shifting of the guide element essentially parallel to the mentioned side face or surface.
From German Patent Specification No. 1,685,571 and the corresponding U.S. Pat. No. 3,470,588, granted Oct. 7, 1969, such a grating is known for a cleaning machine for cotton fibers, in which the bars are provided with guide sheets adjustable in their spacing from a beater. Each guide sheet has a guide surface and a flat portion which rests on the side face of its bar directed towards the beater, the bar being inclined to the tangential direction of the beater envelope.
The spacing of the guide sheets from the beater is of considerable importance for the perfect separation of impurities from the fiber material. Accordingly, it is important that such spacing can be exactly set.